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Here is my second question, I know 1000 grams of water is 1 liter. But does the density affect the result? What if the substance is mercury?

When you add seed crystal in to a supersaturated solution, the solute comes out. Does this make it saturated? Is what came out the extra solute that make it supersaturated? Or is it all the solute? This is my first question.

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  • $\begingroup$ These are completely unrelated questions and should be asked separately. $\endgroup$ – bon Nov 8 '15 at 18:48
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$1000 \, \text{g}$ of water occupy a volume of (approximately) $1 \, \text{L}$ because the density of water is (approximately) $1000 \, \text{g/L}$. If you had $1000 \, \text{g}$ of mercury, whose density is $13534 \, \text{g/L}$, it would occupy a volume of $0.0739 \, \text{L}$.

Usually you can only dissolve so much of a solute into a solvent until a certain threshold is reached. When this threshold is reached you have a saturated solution. After that point, it is thermodynamically more favourable (under the given conditions, e.g. temperature, pressure, etc.) for any extra solute not to get dissolved in the solvent but clump together and precipitate. But if you use some special techniques you can prepare a supersaturated solution that contains more solute than it should, thermodynamically speaking. A supersaturated solution is a meta-stable state, meaning that it is only a local energy minimum for the system, not the global minimum. But it would like to get to the global minimum if it gets the chance. The only thing preventing that, is a small energy barrier that has to be surmounted. So, if you disrupt the supersaturated solution in any way, like shaking it or adding a crystal seed, the solution can surmount the energy barrier and attain its global minimum state, i.e. the saturated state.

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  • $\begingroup$ Ok, after the crystal seed was added, the supersaturated solution becomes saturated? $\endgroup$ – most venerable sir Mar 11 '14 at 2:12
  • $\begingroup$ @user132522 Yes. $\endgroup$ – Philipp Mar 11 '14 at 2:13
  • $\begingroup$ And also, talk about recrystalization, or any other way to retrieve the solvated particles. $\endgroup$ – most venerable sir Mar 11 '14 at 2:14
  • $\begingroup$ @user132522 I'm not sure, if I understand you right, but if you want to retrieve the solvated particles you have to get rid of the solvent or change the condition such that the solubility of your solute decreases and it precipitates. $\endgroup$ – Philipp Mar 11 '14 at 2:18
  • $\begingroup$ Do you know the graph of solubility of salts. $\endgroup$ – most venerable sir Mar 11 '14 at 2:19

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